When I started investigating a news story about the possible cause of King Tutankhamen‘s death, I never expected to end up on the trail of his penis.

As I’ve reported today, a letter published in JAMA this week suggests that contrary to what was said earlier this year, the boy pharaoh did not die of a combination of an inherited bone disorder and a nasty case of malaria, but of a genetic disease called sickle-cell anemia.

This letter is just one of six comments that JAMA has published on the work, carried out by Egypt’s chief archaeologist Zahi Hawass and colleagues. Another one suggests that Tut and his relatives may have suffered from a hormonal disorder that is similar to Antley-Bixler syndrome. In this singularly interesting syndrome, a single genetic mutation causes elongated skulls, and over-production of oestrogen. Male sufferers can have distinctive physical features, including breasts and under-developed genitalia.

Irwin Braverman of Yale Medical School and Philip Mackowiak of the Veterans Affairs Medical Center in Baltimore, Maryland, believe that a variant of this syndrome could explain why artwork from the time depicts Tut and his relatives – in particular his father Akhenatun – as having feminine bodies, with hips and breasts, and particularly long heads.

Hawass dismisses the idea, in part because Tut’s penis is, as he puts it, “well-developed”. But on closer scrutiny of his paper, I spotted a note admitting that the penis in question is no longer attached to the king’s body.

I smelled a conspiracy. Could ancient Egyptian embalmers have replaced the royal member to hide the fact that their king’s manhood was somewhat lacking? What’s more, the front of Tut’s chest is missing, so it’s impossible to check whether he did indeed have breasts. Was this part of the mummy’s anatomy sabotaged too?

I called John Taylor, who looks after the mummies collection at the British Museum in London. When Tut’s mummy was first unwrapped in 1922, he reassures me, “the penis was there and was attached”.

The breakage must therefore have occurred in modern times, perhaps during a particularly brutal autopsy. (The wayward penis was reported missing in 1968, before it was discovered again during a CT scan in 2006, lying in the loose sand around the mummy’s body.) The chest cavity was also damaged in modern times, probably by Howard Carter’s team in 1922.

None of this, however, rules out the possibility that he had a hormonal disorder. Braverman theorises that the royal family could have carried a mutation in a related gene, which would cause deformed skulls and breast formation, without affecting genitalia or fertility. Detailed photographs of the skull of Tut’s father, Akhenatun, could help to confirm the idea, but as yet these have not been seen by researchers outside Hawass’s team. Conspiracy theorists may have something to hang onto after all.